Rotary blower or engine



(No Model.)

G. GROWELL.

ROTARY BLOWER OR ENGINE. No 475,302. Patented May 24, 1892.

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GILMER OROYVELL, OF BROOKLYN, NEIV YORK.

ROTARY BLOWER OR ENGINE.

' SPECIFICATION forming part of Letters Patent No. 475,302, dated May24, 1892.

Application filed April 3, 1890. Renewed October 19, 1891- Serial No.109,091- (No model.)

To aZZ whom it may concern.-

Be it known that I, GILMER CRoWELL, a citizen of the United States,residing at Brooklyn, in the county of Kings and State of New York, haveinvented new and useful Improvements in RotaryBlowers orEngines, ofwhich the following is a specification.

This invention relates to that type of rotary air-blast fans, blowers,or engines wherein a rotating drum is eccentrically journaled within astationary cylinder or case and carries a radially sliding piston havingno springs, packings, or followers. In this type of blower or engine itis exceedingly difficult to obtain perfect and satisfactory results fromthe fact that there are points in the diameter of the stationarycylinder where both ends of the piston do not accurately fill thecylinder, in consequence of which leakage and loss of power or pressureresults. For this reason a sliding piston having no springs or packingsor followers and carried by a drum eccentrically journaled in acylindrical case has never, so far as I know, been practicably used forany considerable length of time.

The objects of my invention are to avoid the above objections, toprovide a novel construction whereby the radially sliding fan blades orpistons touch and accurately fit diametrically-opposite points at everypart of the internal caliber of the stationary cylinder withoutemploying springs or packings or followers, an'd to provide a novel fanblade or piston for this special type of blower or engine. To accomplishthese objects, my invention involves the features of construction, thecombination or arrangement of parts, and the principles of operationhereinafter described and claimed, reference being made to theaccompanying drawing, in which the figure is a vertical centralsectional View of sufficient of the air-blast, blower, or engine toexhibit theimprovements claimed.

In order to enable those skilled in the art to make and use myinvention, I will now describe the same in detail, referring to thedrawing, whereinerwise laterally adjust the cylinder in the boringmechanism and bore it on a center (indicated by the numeral 3,) which isslightly eccentric to the center 2, so that the internal caliber isthereby struck from two different centers and not more than two. Thisforms the internal surface with a single long crescent-shaped concavity,as at4, which vanishes at the points 5 into the true circular part 6. Bythis construction the diameter of the internal caliber is increased atthe diametrical line '7 8, and at this point the said diameter isco-ordinate with the diameter at the diametrical line 9 10. This isessential for the perfect Working of the radially-slidin g fan or pistonblades 12, carried by a rotating drum 13, j ournaled eccentrically inthe stationary cylinder. As there is a positive measured distance acrossthe cylinder on theline7 8, which is co-ordinate to the distance acrossthe cylinder on the line 9 10, the opposite extremities ofthe fanorpiston blades 12 will in their revolution preserve accurate and closecontact or fit throughout the diameter of the internal caliber withoutliability of leakage at any point past a blade, whereby I attain byactual demonstration twenty per cent. increased power or pressure in theworking of the blower 01' engine. WVhether the fan or piston blades bedriven or serve to drive is immaterial, and therefore I do not enterinto further detailed illustration and explanation in this respect,

as it is not essential for the proper understanding of my improvement.

It has been proposed to strike the internal caliber of a cylinder fromthree different centers; but the construction has never been worked inconsequence of the impossibility of obtaining fan blades or pistons thatwill practicably operate con j ointly therewith and avoid leakagewithout using spring followers or packings and the like, for the workingfluid will at points in the cylinder blow past the extremities of thepistons.

The axis of the rotating drum in my construction is composed of athrough-shaft 14, journaled eccentrically in the cylinder-heads, andthat the fan-blades may be practically continuous in a radial line theyokes 15 each have a longitudinal slot 16, so that the shaft passesthrough the yokes, while the latter are free to slide back and forth.The fan-blades are rigidly secured to the opposite ends of the yokes andthe extremities of the blades are convex and touch and accurately fitsuperficially the inside of the stationary cylinder. While the drum isjournaled eccentrically in the cylinder and the internal diameterthereof is struck from two difierent centers, still the extremities ofthe fan-blades accurately fit the cylinder at every point in therevolution of the fan, and there is no possibility of the air or otherfluid blowing past the extremity of a blade, whereby the power of theengine is enlarged and good results attained.

The method of obtaining the center 3 will be clearly understood by thefollowing explanation: The center 3 must be on the line indicated by thenumeral 17, and to obtain this line it is drawn through the center 2 towhere the line 7 intersects the circle 6 at the top of the casing, asshown. This determines the angle of the line 17, and on this line at theproper distance from the center 2 the second center 3 is formed thatwill strike the crescent 4, whereby the distance or diameter on the line7 8 will be the same as the distance or diameter on the line 9 10. Thisproduces what I term a perfectly-fitted cylinder, since a definitelength of fan-blade working in the eccentric drum will accurately fitthe interior of the cylinder at every point.

Having thus described my invention, what I claim is 1. The combinationof the stationary cylinder having its'internal caliber struck from twodifferent centers only to form the single crescent-shaped concavity andleave the remainder of the caliber truly circular with the drumeccentricallyjournaled in the cylinder, and a fan or piston bladesliding radially and having its' opposite extremities superficiallybearing against the inside of the cylinder, substantially as described.

2. The combination of the stationary cylinder having its internalcaliber struck from two different centers only to form the singlecrescent-shaped concavity and leave the remainder of the caliber trulycircular with the drum, the through-shaft journaled eccentrically in thecylinder-heads, and the slotted yokes carrying the fan or piston bladesand sliding on the shaft, with the fan or piston blades having theirextremities in superficial contact with the internal caliber described,substantially as set forth.

In testimony whereof I have atlixcd my signature in presence ofwitnesses.

A GILMER CROWELL.

\Vitnesses:

ISAAC ROBERTS, WILLARD R. EAMES.

